Pro-wood heat group opposes more time to sell dirtier stoves


On November 21, 2018, the EPA announced it was taking comment on a 2-year sell-through provision for wood stoves and on other issues in the 2015 wood heater regulation. The Alliance for Green only submitted comments on the 2-year sell-through that would allow manufacturers to build and sell Step 1 wood and pellet stoves that emit up to 4.5 grams an hour and retailers to see them until June 15, 2022.  All stakeholder comments will be available to the public by going to www.regulations.gov and typing in EPA-HQ-OAR-2018-0196. 

Comments of the Alliance for Green Heat
Responding to

The United States Environmental Protection Agency
Comments on the Advance Notice of Proposed Rulemaking; Standards of Performance for New Residential Wood Heaters, New Residential Hydronic Heaters and Forced-Air Furnaces

Docket No. EPA-HQ-OAR-2018-0196

Feb. 13, 2018

The Alliance for Green Heat (AGH) offers the following comments on the U.S. Environmental Protection Agency’s (EPA) Advance Notice of Proposed Rulemaking (ANPRM),Standards of Performance for New Residential Wood Heaters, New Residential Hydronic Heaters and Forced-Air Furnaces, published at 83 Fed. Reg. 61,585 (Nov. 30, 2018). 

AGH is a national, non-partisan, non-profit association that promotes advances in wood stove technology to ensure that wood and pellet stoves become steadily cleaner and more efficient.  AGH has held four Stove Design Challenges to highlight the potential of innovative design in wood and pellet stoves and to educate policymakers and consumers.

AGH opposes any proposal to provide “sell-through” periods or to extend other compliance deadlines when there are sufficient products available that comply with EPA’s applicable standards.  Achievable emission regulations, such as EPA’s NSPS for New Residential Wood Heaters, New Residential Hydronic Heaters and Forced-Air Furnaces, are based on levels that manufacturers can meet through the use of technology that has been adequately demonstrated for the source category. These standards, that recognize such demonstrated technologies, are vital to driving the innovation process that encourages more manufacturers to develop and manufacture cleaner and more efficient stoves.  

1.    There is no technical or legal justification to change the timeline for Step 2 compliance

EPA fails to provide any compelling technical or legal basis to justify aproposed sell-through for wood stoves.  The assertion that some manufacturers and retailers would financially benefit from a delay or sell-through is not consistent with the mandates of section 111.                                                                                                                                      
Section 111(a)(1) of the Clean Air Act defines “standard of performance” as  “a standard for emissions of air pollutants which reflects the degree of emission limitation achievable through the application of the best system of emission reduction . . . .”  42 U.S.C. § 7411(a)(1) (2013) (emphasis added).  The proposal in the ANPRM to revise the applicable deadlines does not explain why such an approach would be consistent with the requirements in section 111.  Moreover, when developing the NSPS in 2015, EPA already took into account the cost of achieving the applicable standards as well as the available technology, which is why the Agency provided 5 years for the implementation of the Step 2 standards. The ANPRM fails to state how a sell-though is consistent with the requirements in section 111 and presents no other legal justification. 
2.    The 5-year timeline in the 2015 NSPS was sufficient

The 5-year timeline provided in the 2015 NSPS was sufficient for achieving the environmental and innovation goals of the NSPS while providing flexibility to industry.  AGH supports the timelines outlined in the 2015 NSPS that allows industry flexibility during the period between 2015 and the 5 years following.  Indeed, at the time these deadlines were promulgated, industry and EPA agreed that these time frames were sufficient for industry to transition to cleaner stoves.  Unfortunately, given the information in the record for this ANPRM, it appears that industry has been spending more resources on obtaining time extensions from Congress, the Executive Branch, and the courts than devoting such financial support to research and development (R&D) and testing.  

3.    A sell-through is not justified to protect non-catalytic stoves

Apparent from the docket for this rulemaking, a form letter comments for retailers made it easier for this market segment to comment on the need for a stove sell-through.  Much of that letter made the case that the range of choice of non-catalytic stoves for consumers would diminish.  The letters noted that, while “traditional catalytic wood heaters on the market today might meet the Step 2 requirements” in the lab, the stoves on the market may not meet the requirements “over a lifetime of realworld, in-home use.” The letter went on the express confidence that “[n]ew technologies will emerge as the result of regulation with technology that will surpass Step 2 emission limits while maintaining the ease of operation that consumers demand through the lifecycle of the stove.”

This assertion in the form comment letter has simply not played out in the market.  AGH notes that 27 models of non-catalytic stoves had achieved 2020 compliance as of October 2018, and that number will likely rise when the EPA next updates the list of certified wood stoves.  While the ratio of catalytic to non-catalytic models of stoves will rise, AGH believes it is premature to artificially protect the market for non-catalytic stoves by extending a sell-through to all classes of stoves, including pellet stoves.

AGH also highlights the rise of “hybrid stoves,” stoves that use both catalytic and non-catalytic technology to reduce particulates.  These stoves offer more options to homeowners to reduce particulates, options neither catalytic nor non-catalytic stoves can fully provide on their own.

         4.    Insufficient cost data on Step 2 stoves

While we are likely to see a small rise in the price of many stoves as a result of Step 2 compliance, there is a noticeable lack of data supporting such a conclusion.  The consolidation of models may help manufacturers sell more of each model, which is likely to help keep impacts on the price of stoves to a minimum.  Some stove prices may decrease or remain the same, as we saw when some uncertified stoves were required to become certified in 2015.  Prices of stoves are likely to be equally, if not more greatly, impacted in a positive way by improved automation processes, and in a negative way by tariffs and prices of steel. 

    5.    Insufficient data on the assertion that consumers will hold off buying new stoves

There is very little data about the proportion of consumers buying a wood or pellet stove for the first time, as compared to those who are replacing an older stove.  And often families switch from wood to pellet stoves, or vice versa.  First time stove buyers and those who will buy a stove anyway, may be far more numerous than those who would have bought a new stove if it were $ 100 cheaper. Trends show that extremely affordable stoves are still available at big box stores, including some Step 2 models. What may be more likely to occur is that more consumers will buy the more affordable stoves from big box stores instead of specialty hearth stores. There also are a growing number of certified stoves on the second-hand marketplace; these stoves still offer a better alternative than even older, uncertified stoves.   We hope that this comment process results in more data about the assertion that a sizable population of consumers will hold on to older stoves.  

6.    2018 was a great year for stove sales

Industry argues that manufacturers do not have the resources to undertake the certification process for Step 2 stoves, and that retailers cannot financially weather the transition.  Wood stove and especially pellet stove sales are significantly influenced by cold winters, the state of the economy and other factors which can be more significant than this NSPS. However, we note that industry – both manufacturers, retailers and chimney sweeps — have just experienced a very successful year.   A successful 2018 is helping to propel industry in the final leg leading up to 2020.  

Hearth & Home magazine routinely interviews retailers about the state of their businesses.  Only one retailer in the February 2019 issue mentioned maintaining an inventory of Step 1 products, and the retailer did not express concern regarding the business climate. The majority of retailers sell hearth, patio and barbecue products, and often the retailers express viewpoints regarding all three sectors. These magazine interviews also show that retailers have increasingly diversified products.  We reproduced all the specific comments about stoves in the February 2019 issue of Hearth & Home.  Reproduced below are retailer comments from pages 68 – 70 of the magazine. To protect the identity of the retailer, the magazine only quotes identify the state in which the retailer resides rather than the name of the retailer.

Arkansas: “2018 turned out to be a good year overall.”

California: “We have been in business for 33 years and this was the best year yet.”

California: “Hearth department was up 8%.”

Connecticut: “This was one of our top Decembers since we’ve been in business; 2019 looks to be a great year, even though we had a very good 2018.”

Illinois: “Woodburning is slowly fading away, even in a rural wooded area like ours.”

Louisiana: “Our service business is up 67%.”

Nebraska: “Hearth sales were stagnant from 2017.  All in all, business was good, but we’re interested in seeing where the trade war steel prices go, along with tariff surcharges.”

New Jersey: “Another year has flown by.  Solid growth once again.”

Oregon: “We opened a new hearth showroom in fall of 2018.”

Pennsylvania: “Best calendar year in the last five years.  Also, very profitable.”

Virginia: “Wow, what a year!  I’ve worked here for 27 years and have never seen it this busy.  Thanks President Trump.  Business is a boomin’.  Can’t wait for this coming season.  Woo-hoo. $ $ $ .”

Virginia: “2018 ended with record sales and installations of vent-free gas fireplaces, log sets and inserts.”

Wisconsin: “No slowing down in sales of high-end fireplaces, wood and gas.  Wow, what a time in our industry.”

Wisconsin: “Overall year-end we were way up.  Wood seems to be really strong.”

Wisconsin: “Busy year.  Easily could have had greater sales if we could find another good employee.  We have had some warranty issues and manufacturers did not stand behind their product.”

Wisconsin: “Wood and gas fireplaces are strong.  Plain steel wood stoves is a weak spot.  We’re clearing inventory of all non-2020 compliant wood stoves.  Will restock only 2020 compliant.”

7.    The number of stove models will temporarily shrink

While the number of different stove models will temporarily shrink due to the increased stringency of the standards, not all consumers will notice because there will continue to be a variety of products on the market.  Many manufactures are getting around any perceived limitation of products by certifying one firebox, then offering it in a variety of models –  such as with a pedestal, with legs, or even as an insert.   More manufacturers are beginning to offer a variety of stove models, so the standards’ impact on consumers will decrease even further.

8.    There is minimal public support for sell-throughs 

In 2014, EPA received 1,750 Comments in response to proposals that set 2020 as the deadline for Step 2 compliance.  Just 5 years later, the process led by the current administration’s EPA generated only 75 comments for the sell-through for furnaces and boilers, including comments from less than 10 individual citizens.  In addition, there is no state, county or city that supports providing a sell-through for what constitutes the dirtiest appliance class among wood heaters.  Clearly, the populations that are most greatly impacted by such a sell-through, recognize that this deregulatory action increases pollution far more than the financial benefit for manufacturers.
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AGH appreciates the opportunity to submit these comments. If there are any questions regarding any statements above, please contact John Ackerly at 301-204-9562.
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Non-cats cleaner than catalytic or pellet stoves in new certifications

In the most recent updated list of EPA certified stoves, 17 more units became 2020 compliant, meeting the 2020 EPA regulations of emitting no more than 2 grams an hour.  While it is not a large sample size, among this batch of newly certified units,  the non-catalytic stoves averaged 1.2 grams an hour, whereas catalytic stove averaged 1.3 and pellet stoves averaged 1.4.  It is not yet clear if the non-catalytic stove designers used new innovative technology or just fine-tuned existing strategies to reduce particulate matter.
Of the 17 newly certified stoves,
non-catalytic models are the cleanest
Many industry experts have argued that the 2020 emission standard of 2 grams an hour favors catalytic and pellet stoves.  But we are seeing some non-cats come in below 1 gram an hour, including 2 of the 5 in this recently certified batch.  Many of the 2020 compliant non-cats do fall in the 1.5 to 2 gram range.  And every once in a while, a stove goes into the lab and doesn’t quite meet the 2.0 gram standard, like a IHP stove that recently came out certified at 2.1 grams.  Assuming this unit was not tested with cordwood (which are allowed up to 2.5 grams per hour), this means that the model can only remain on the market in the US for less than 18 months until May 2020, unless the EPA were to approve a sell-through.
Efficiency

The average efficiencies show a less surprising trend: the 13 newly certified non-catalytic and pellet stoves had the same average efficiency – 69%.  The four catalytic stoves, including one hybrid, had an average of 77% efficiency.  These efficiency numbers are typical of averages of all stoves on the market. Pellet stoves have long had the reputation of being a more efficient technology, but over the last several years, as manufacturers were required to disclose efficiencies,  we saw that pellet stoves had a far greater range on the low and high end, with the average being about the same as non-cats.  Even among this small sample, pellet stoves had the lowest efficiency unit (at 60%) made by Sherwood Industries.  Sherwood also made the highest efficiency pellet stove in this newly certified batch – at 77%.
Efficiency could be a more important metric if Congress re-instates the tax credit for residential wood heaters.  That credit was worth $ 300 but expired in December 2017.  Stoves needed to be 75% efficient to qualify for the tax credit, but manufacturers were allowed to claim eligibility without disclosing their real efficiency, allowing virtually all stoves to qualify.  The practice of exaggerating efficiencies and misleading consumers got to the point that even the industry association, the Hearth Patio & Barbecue Association, changed course in 2018 and recommended that only publicly disclosed efficiencies on the EPA list of stoves be used in the future to determine eligibility.  If the credit is reinstated, there is a chance that the eligibility number could be reduced to 73%, in part to help more non-catalytic stoves qualify.
Carbon monoxide

The other metric that test labs are now required to report is carbon monoxide, another very important test of cleanliness, along with particulate matter.  By far the cleanest technology in terms of CO is the pellet stove. The pellet stoves in this small batch had an average of 0.42. grams an hour of CO, the catalytic had 0.63 grams and non-catalytic stoves had 1.2 grams – almost double the CO of non-cats and triple that of pellet stoves.

A stove’s ability to burn off carbon monoxide often tracks its ability to burn off particulate matter.  Of the pellet stoves, the three with the lowest CO also had a lower average PM (1.2 grams an hour), and the three with higher CO had a higher average PM (1.5 grams an hour).  
Overall progress towards 2020

There are 533 stove models on the latest list of EPA certified stoves that are currently in production.  Many of those units will never be changed to become 2020 compliant and many are already not being produced any more.  Industry experts say that the number of stove models will contract as we get closer to 2020, likely in the range of 300 – 400 models.  As of February 2019, 119 models are 2020 compliant.  (The number of 2020 compliant models is consistently under-reported due to delays in processing and notification.)  Many manufacturers may also have completed their R&D and/or their testing but have not submitted the data to the EPA. 
Most stove manufacturers have at least a third to half of their models 2020 certified – including larger brands such as American Energy Systems, Blaze King, Even Temp, Fireplace Products International, Hearthstone, Pacific Energy, Rais, Ravelli, RSF/ICC, Sherwood Industries, Stuv, Travis and Woodstock Soapstone.
However, the two largest value stove manufacturers in the US market – US Stove and Englander – only have pellet stoves certified and still do not have any 2020 compliant wood stoves.   They sell to big box stores, which buy even earlier than specialty retailers.  It is still too early to tell if big box stores will replace Englander and US Stove models with models from other manufacturers, likely at higher prices.  Some in industry hope that the 2020 emission standards will help specialty heath stores regain some of the market share they had lost to the big box stores over the past decade.  

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Maryland program helps residents install cleanest stoves on the market

Chris Clark manages the clean wood and
pellet stove program for the Maryland
Energy Administration.
A Maryland renewable energy rebate program established in 2012 has provided assistance to nearly 3,000 to purchase and install cleaner, modern wood and pellet stoves.  The program was designed to help rural families, who were least likely to benefit from solar and other renewable energy programs.
The state has invested $ 1.88 million dollars, or an average of $ 664 per home.  The average purchase and installation costs of a stove is often around $ 3,800, so the state would be providing less than 20% of the price tag for a significant reduction in a home’s annual fossil fuel footprint.
The Maryland Energy Administration who manages a suite of renewable energy incentives runs the program.  With this program, the MEA cannot exactly track the amount of fossil fuel that the program has reduced, which hinders the ability of regulators to track data as they can with the solar and other rebate programs.
Of the 2,845 stoves purchased through the program, 2,425 or 85% were pellet stoves.  To be eligible, pellet stoves have to emit 2 grams an hour or less, and wood stoves 3 grams an hour or less, well below the federal EPA limit of 4.5 grams an hour.  Pellet stoves are eligible for a $ 700 grant and wood stoves $ 500.

Rebate data provided by MEA
“We are pleased that this program steers so many people towards pellet stoves and ensures that the installation is done professionally,” said John Ackerly, President of the Alliance for Green Heat, a Maryland based group that worked with MEA to establish the program. 
Only residents who do not have access to natural gas are eligible for the grant, which as a result helps families in rural areas who rely on more expensive fossil heating fuels.  New York also adopted this innovative approach, and only provides incentives to homes that are not on the natural gas grid.  A 2013 analysis of the program by the Alliance for Green Heat found that it was helping less affluent families to reduce fossil fuel use.
The program does not require residents to turn in an old, uncertified wood stove to participate in the program.  However, some retailers report that nearly half of their customers who use this program turn in an old stove that is recycled. 
During 2015, the program experienced its highest participation rates, providing grants for 1,036 stoves, 904 of which were pellet stoves. 

“A $ 3,000 pellet stove installation can reduce fossil fuel usage by as much as a $ 15,000 array of solar panels,” said Ackerly.  “And increasingly, we see families who have solar panels also installing pellet stoves so that they can use renewable energy for both their electric and heating needs,” he added.

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HHT and Ravelli concur to launch performance for 5 stoves

In reaction to a Independence of Information Act request filed by the Alliance for Inexperienced Warmth, Fireside &amp Residence Technologies (HHT) and Ravelli unveiled real effectiveness figures for many of their common pellet stove models.&nbsp Efficiencies ranged from fifty six% to 76%.
Wooden and pellet stoves certified after May 2015 must take a look at for and disclose their performance to consumers, as necessary by new EPA restrictions. Prior to these restrictions, stove producers claimed that any accessible performance information was private and they usually did not give it to consumers.&nbsp Nevertheless, several organizations provided the performance information to the EPA as element of the certification process.&nbsp
The Alliance for Environmentally friendly Warmth, based on its legal counsel, argued that the EPA could not keep effectiveness knowledge it gathered prior to May possibly 2015 private since it was based mostly on emission knowledge, and emissions data can’t be private.&nbsp In July 2015 the EPA declined to launch the efficiencies to the Alliance, in keeping with its longstanding apply that they would hold all data private if it was submitted as Private Business Details (CBI). &nbsp
At first, the Alliance experienced questioned for the weighted typical efficiency as nicely as the effectiveness from each and every of the 4 burn charges that labs use to take a look at stoves.&nbsp The Alliance agreed to drop the ask for for the individual burn price efficiencies and only request the average.&nbsp Primarily based on that adjust, HHT and Ravelli agreed to allow the EPA to launch their effectiveness figures to the Alliance with some conditions.
The EPA provided a closing reaction with a data sheet (pdf) hooked up.&nbsp The performance figures (HHV based on B415.1) from that knowledge sheet are:
Organization&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp Model&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp Effectiveness
HHT&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp Accentra 52i insert&nbsp &nbsp seventy six%
HHT &nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp Mt Vernon E2&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp seventy five%
HHT&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp Mt Vernon AE&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbspseventy one%
Ravelli&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp RV100&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp70%
Ravelli&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp RV80&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbspfifty six%
The Alliance asked for effectiveness data for these certain models, together with numerous other folks, due to the fact we have been in the process of independently tests a assortment of pellet stoves.&nbsp The Alliance was also attempting to encourage the EPA to change their coverage and disclose all effectiveness knowledge, even if that performance information had been marked as Private Organization Details.&nbsp The Alliance argued &nbsp&nbsp
The Ravelli RV80 was tested at
fifty six% efficiency by a EPA
accredited test lab.

that performance was of these kinds of standard significance to shoppers and that maintaining it confidential served no valuable goal. That try was unsuccessful. &nbspThe Alliance is not appealing.

The 5 freshly unveiled real effectiveness figures are not incorporated on the EPA’s record of qualified stoves, the place about 20% of the stoves have real efficiencies outlined. &nbspExcept for a single of the Ravelli’s, these five stoves all have about average or above common efficiencies.&nbsp&nbsp The Ravelli RV80 is only fifty six% successful.&nbsp Nearly all stoves assert to be seventy five% successful to be qualified for the $ three hundred federal tax credit, and EPA listing or disclosure that reveals the stove is not even 60% successful does not appear to deter companies from continuing to claim eligibility for the tax credit rating.&nbsp &nbsp

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Downdraft Wooden Stoves: Consumers Beware

The simplicity of the non-catalytic stove helps make it the most well-known sort of stove in North The united states by much.&nbsp With most non-cats, the buyer only requirements to fret about a one lever to regulate the quantity of air in the firebox.&nbsp But some shoppers unwittingly buy a extremely unique sort of non-cat, a &nbspdowndraft stove, and often regret it.

These days there are only a handful of downdraft stoves on the marketplace, Most have been pushed apart by non-cat stoves with air tubes that reburn smoke as it exits the firebox.&nbsp The downdraft stove works with a next lever that engages a by-move damper which forces the smoke down into a chamber the place heat can reburn it ahead of it goes again up the chimney.&nbsp
Nearly all stoves on the industry today do not consider to get smoke to go down, but rather try out to reburn it on its journey upward with secondary air launched by way of holes in tubes or in higher wall of stove – or with a catalyst. Hybrids use the two tubes to inject for secondary air and a catalyst. &nbsp(Click below for a lot more on cat, non-cat and hybrid stoves.)
Downdraft stoves tend to be finicky, require to be really sizzling to function appropriately and are far more inclined to leaking smoke into the property.&nbsp Most buyers must not take into account them until they know what they are obtaining into and are ready to be a lot a lot more engaged with their stove.&nbsp The same can be said about catalytic stoves.&nbsp Customers should comprehend that they need to know how to use the next lever that engages the by-move damper and from time to time check the catalyst, and exchange it when it requirements replacing.

Stove modify out applications, that switch out outdated stoves with new, EPA certified types could want to exclude downdraft stoves from eligible replacements as they could be the most difficult class of stove to operate regularly without having seen smoke.

The downdraft stove turned common in the 1980s when Vermont Castings employed it to extract much more heat from a stove and to support go the emission testing required by the state of Oregon, and later by the EPA. &nbspThe by-go damper aided sluggish down the hearth, create turbulence, and extract a lot more warmth from the very hot gases ahead of they went up the stack. The Resolute Acclaim, a single of the most well-known wooden stoves of the final century, was a downdraft stove.&nbsp It clocked in at 3.4 grams for each hour and ongoing selling via the 2000s, but has given that been taken out of creation.
Today, there are a handful of downdraft stoves on the industry, including the Lopi Leyden and the Avalon Arbor (which are evidently the same stove).&nbsp The&nbspHarman TL300 is also a downdrafter and Vermont Castings still has one particular or two.
The authentic Frankin stove
was a downdraft with no
front door and typically
created for a smoky house.

Downdraft stoves have existed for centuries in numerous patterns. The authentic stove invented by Ben Franklin also experienced a downdraft included into the layout, and it is a single of the causes that the stove was so finicky and disfavored by the greater part of buyers. Franklin himself admitted that the stove was tough to function and took lots of interest and was not anything that “could be left to the servants.” &nbspLater iterations of the Franklin stove included a doorway and most received rid of the downdraft.

Customer feedback
Hearth.com is a leading chat place for wood stove specialists and rookies alike. It consists of a good deal of very good suggestions on downdraft stoves:
– “The creosote smell when closing the bypass is not an uncommon situation with the downdrafting stoves. I’ve seen Harman stove owners complain with it as nicely. I will often get it. Occasionally not. It is not noxious, just a faint odor that I can do with out. CO keep track of pays it no head.”
– “I want a team of downdrafters could get their heads collectively on this a single and figure out what is likely on. It really is a frequent problem to different stoves. Possibly that box complete of smoke is permitting some escape at the joints.”
– “I’ve smelled it when the draft was robust, but typically it comes when the flue has begun to awesome down a little. Loading lid was a key suspect, but I regasketed it and sat a solid iron pot on there.”
– “Downdraft stoves are notoriously fussy and demanding of a robust draft.”
– “The Leyden has gone through a handful of modifications of the several years. There are some ports that require complete cleaning “Regular monthly” as properly and they are not effortless to get to. Make certain these ports are cleaned frequently. Your guide shows how to do this properly.”
– “These stoves have to be critically very hot to perform.”
– “I occasionally get a bit of smoke when loading. Mainly due to the fact I am way too lazy to do it proper. Once more, operate the stove as developed and if it will not perform, get a appear at the flue, check out for ash buildup, etc.. … your flue style is gonna be a tough one.”
– “I don’t want to melt your stove down, but my hunch is that you might be not acquiring it sizzling enough on a three-four” coal mattress.”
– “Is the wooden really properly seasoned? That is very important with this stove as is a good draft.”
– “I would try working your stove leading temperature a small larger (650-seven-hundred) prior to you go to secondary melt away, generally you get some fall in stovetop temperature when you near the damper.”
– “The Lopi Leyden is a extremely problematic stove. You don’t want it, imagine me!”
– “I also propose to consider off the Vermont Castings Resolute and Lopi Leyden. Equally use a various system to obtain a thoroughly clean burn up than the other non-catalytic stoves. The two stoves typically have a steeper understanding curve, can be vulnerable to expensive repairs and are greater suited for entire-time burners which does not look to be your intention.”
– “As other individuals have talked about, the Oakwood (and other downdrafts like Lopi Leyden and specified Vermont Castings types) can be a little bit fussy about dry wood and good draft, requires a little bit a lot more babysitting and for a longer time studying curve, and is not well suited to slower/reduced burns in months like November and April.”
– “You want a stove with tubes in the leading or a catalyst. Avoid stoves that attract smoke down into the back of the stove. For instance: Vermont Castings, some Harman’s and Lopi Leyden.”

Heated Up!

Wooden and pellet stoves with true efficiency quantities

The following seventy one wood and pellet stoves have been tested by accredited laboratories for efficiency. Buyers should consider acquiring 1 of these stoves if they want a stove that has a trustworthy effectiveness value. &nbspHowever, with wood stoves, the shown efficiency signifies what shoppers can get if they use dry wooden and give the stove ample air. &nbspWith pellet stoves, the performance described by the lab is a great approximation of the effectiveness the customer can expect. &nbsp

Consumers need to beware that most producer websites put up unreliable and exaggerated efficiencies, besides for a tiny team of businesses. &nbspSome businesses could not put up the efficiencies of their pellet stoves due to the fact they are poorly developed and have efficiencies below sixty five%. Simply click right here for an analysis of stove efficiencies.
How to go through this chart: Some of the Model Names have been shortened to in shape into the structure of this weblog. &nbspTo check out the formal supply of accredited stoves that would include the total product name(s), refer to the record of EPA licensed stoves. &nbspThe emission price is the quantity of grams of particulate issue that make up smoke, per hour. The genuine efficiency refers to a typical of the range of heat outputs that the stove is capable of, calculated using the CSA B415.one-ten, which makes use of the larger heating worth (HHV). Below type of stove, “Cat” refers to catalytic stoves, “Hybrid” refers to stoves that have the two catalytic and non-catalytic engineering, and “Non Cat” refers to non-catalytic stoves.

Manufacturer Title Product Identify Emission Fee G/Hr True Performance&nbsp Kind
Kuma Stove Inc. Sequoia 2.2 eighty four Cat&nbsp
Blaze King Industries KEJ 1107&nbsp 1.eight eighty two Cat&nbsp
Woodstock Soapstone Best Metal&nbsp 1. 82 Hybrid&nbsp
Blaze King Industries Princess PEJ &nbsp two.four 81 Cat&nbsp
Blaze King Industries Princess 35&nbsp 2.one eighty one Cat&nbsp
Ningbo Hongsheng Comfortbilt HP5 2.five 81 Pellet
Regency (FPI) Regency 3500 one.1 81 Cat&nbsp
Woodstock Soapstone Development Hybrid&nbsp one.three eighty one Hybrid&nbsp
Blaze King Industries Ashord Chinook&nbsp .eight 80 Cat&nbsp
Blaze King Industries Princess Insert &nbsp 2 eighty Cat&nbsp
Regency (FPI) LG Flushwood one.eight 80 Cat&nbsp
Travis Industries Insert Hybrid&nbsp .six eighty Hybrid&nbsp
Travis Industries Cape Cod&nbsp .five eighty Hybrid&nbsp
England’s Stove Functions 25-SSP01 .56 seventy nine Pellet
Regency (FPI) F5100&nbsp 1.5 seventy nine Cat&nbsp
Travis Industries Rockport .eight seventy eight Cat&nbsp
Seraph Industries Genesis 108 2.1 seventy eight Pellet&nbsp
Blaze King Industries Chinook Sirocco&nbsp one.three 77 Cat&nbsp
Jotul North The united states&nbsp F55 3.5 seventy six Non Cat
Travis Industries Modest Flush &nbsp&nbsp .nine 76 Hybrid&nbsp
Blaze King Industries Chinook Sirocco&nbsp one. 75 Cat&nbsp
Jotul North The us&nbsp F118 CB three.5 75 Non Cat
Pacific Power Hearth TN20 two.one seventy five Non Cat
Pacific Power Hearth Neo 1.six, Insert three.nine 75 Non Cat
Pacific Energy Fireplace&nbsp Neostone 1.6 three.four seventy five Non Cat&nbsp
Sherwood Industries Enviro 1700l 4.five seventy five Non Cat
Jotul North The usa&nbsp F600 four.one 74 Non Cat
Jotul North America&nbsp F45 2.3 74 Non Cat
Jotul North The united states&nbsp F500 three.two 74 Non Cat
Pacific Strength Hearth Neo two.5, insert&nbsp two.nine seventy four Non Cat&nbsp
Travis Industries Evergreen three.six seventy four Non Cat
Travis Industries 42CVT Wooden .seven 73 Cat&nbsp
American Strength Sys. Baby Country S one seventy three Pellet
Boru Stove Firm Carraig Mor&nbsp three.9 seventy three Non Cat&nbsp
Jotul North The usa&nbsp F118 Black Bear three 73 Non Cat
Jotul North The usa&nbsp Tamarack 4.four 73 Non Cat
Jotul North The us&nbsp F3CBII 3.8 73 Non Cat
Jotul North The us&nbsp F602 CB 3.four seventy three Non Cat
Jotul North The usa&nbsp F100 Nordic three 73 Non Cat
Kuma Stove Inc. Ashwood 3.5 seventy three Non Cat
Kuma Stove Inc. Scot HT-one 3.five 73 Non Cat
Kuma Stove Inc. Wooden Basic three.3 73 Non Cat
Travis Industries 42CVT Hearth .7 73 Non Cat
Unforgetable Fire Katydid one.9 73 Non Cat
Jotul North The us&nbsp 50TL two.eight seventy two Non Cat
Kuma Stove Inc. Aspen four.one 72 Non Cat
Sherwood Industries Enviro 1200, i&nbsp 3.four seventy two Non Cat&nbsp
American Strength Sys.&nbsp Minor Rascal 1.one 71 Pellet
Blaze King Industries Briarwood II/ninety&nbsp 3.5 seventy one Non Ca&nbsp
Fireplace &amp House Tech. Mt. Vernon AE 1.seven 71 Pellet
Hearth &amp Home Tech. Accentra-2 .62 71 Pellet&nbsp
Jotul North The us&nbsp C550 CB 4.five 71 Non Cat
Jotul North America&nbsp F602 CB&nbsp 3.4 71 Non Cat&nbsp
Even Temp, (St. Croix) Prescott EXP EXL .53 70 Pellet
England’s Stove Functions 15-SSW02 three.five 70 Non Cat
Quadrafire (HHT) Explorer III 2.nine 70 Non Cat
Quadrafire (HHT) Explorer II 2 sixty nine Non Cat
Wiseway Pellet Stove GW1949 one.nine sixty nine Pellet
Jotul North The usa&nbsp Castine F400 3.8 sixty eight Non Cat
US Stove Company 1269E four.2 68 Non Cat
American Power Sys. 3500, 01 &amp 02 1 sixty seven Pellet&nbsp
Fireside &amp House Tech. Advance one.eight 67 Pellet&nbsp
Pacific Energy Fireplace&nbsp FP 25 3.five sixty seven Non Cat
Even Temp (St. Croix) Hastings 1.1 66 Pellet
Even Temp (St. Croix) Ashby-P 1 sixty six Pellet&nbsp
Jotul North The united states&nbsp F370 2.6 66 Non Cat
Enjoyable Hearth, GHP&nbsp WS-2720-B 4.five sixty six Non Cat
Pacific Strength Fireplace PF16 3.one sixty five Non Cat&nbsp
US Stove Company 5660E, one.nine sixty two Pellet
Sherwood Industries EF2, Chatham,&nbsp 1.8 fifty eight Pellet

Heated Up!

Performance of Popular Pellet Stoves

This is an except of a much longer, and more technical paper by Prof. Gael Ulrich’s -“BioCombustion Institute Bulletin #3.” Gael calculated the efficiency of six popular pellet stoves, finding a wide difference.  The highest, the Italian made Piazzetta Sabrina was 76% efficient and the lowest was the Enviro M55 Insert at 51% efficient.  In between were the Ravelli RV80 (62%), Englander PDCV55 (63%), Quadrafire Mt Vernon AE (64%) and Harman Accentra 52i (71%).
He did this by using performance data produced by the Alliance for Green Heat, who tested these 6 stoves over a 30-day period.  The Alliance operated the stoves, often for 24 hours a day, testing them almost every day at various heat output settings and averaging the results. All the stoves were purchased new, without the knowledge of the manufacturers and operated with the same PFI certified pellets.  The Alliance produced an in-depth report about the findings, but we did not report the efficiency values because the instrument we used was a Testo 320, which produces a proprietary European (LHV) number, not the kind of efficiency values that are used and reported in North America. 
Gael’s full paper can be downloaded as a PDF here, which is quite technical.  We reproduced the less technical parts which are accessible to a wider audience. 

One conclusion is that many pellet stoves lack a very simple solution to increasing their efficiencies – larger heat exchangers.  Gael found that “All [the stoves], except the Enviro and Quadrafire, appear capable of adding another 5 to 10 percentage points by increasing heat exchange area to reduce the flue gas temperature.”  This solution may only add $ 100 – $ 200 to the price of a stove but would save consumers far more in fuel costs. 
One thing is clear: more expensive stoves do not necessarily provide consumers with higher efficiency. The Englander is sold by big box hardware stoves for $ 1,100, and is on par or better in efficiency than stoves that sell for $ 3,000 or $ 4,000.  This is significant because the big pellet stove manufactures do not release the actual efficiency of their stoves to consumers and consumers have virtually no way to tell which models are lower or higher efficiency.  The EPA contributed to a myth that pellet stoves have high efficiencies by giving them a default efficiency of 78%.  Emerging data shows the average pellet stove is likely around 70% efficiency, but many big name brands make pellet stoves that have efficiencies in 50s and 60s. This analysis begins to dismantle the lack of transparency in efficiency values that manufacturers have tried to maintain for many years.
Biomass Combustor Efficiency
BioCombustion Institute Bulletin #3
(Gael Ulrich: 16 March 2016)
Abstract
Gael Ulrich was a professor of
Chemical Engineering at the
University of New Hampshire

If flue gas temperature and composition are known, one can calculate the efficiency of a biomass combustor using the so-call “stack loss” technique.  This paper explains in detail why that is possible and how to do it.  Fortuitously, during the preparation of this bulletin, the Alliance for Green Heat published data from their testing of six pellet stoves this past September.[1] Test equipment used in the AGH study delivered composition, temperature, and efficiency numbers.  Investigators declined to report the efficiency numbers for various reasons, although they do mention a range of 60 to 75%. 

Using the AGH temperature and concentration data, I made independent calculations as described in detail herein.  I find one of the six stoves operating at 51% efficiency, three in the low 60s, and the remaining two operating at 71 and 76%.  I also conclude from my analysis that some of these units use “dilution as the solution to pollution.”  If we consider actual emissions in grams per hour or milligrams per MegaJoule of heat delivered instead of parts per million in flue gas, the rating is rearranged with one stove deemed second dirtiest becoming the cleanest and that ranked third cleanest becoming the dirtiest.  Factors that influence efficiency and cleanliness and how to improve these important performance properties are also discussed herein.  
Introduction
As pointed out in BCI Bulletins #1 (Units) and #2 (Emissions), biomass is intrinsically a clean fuel composed primarily of carbon, hydrogen, oxygen, and ash.  If burned properly, with ash un-entrained, flue gases from biomass can be as clean as those from natural gas and perhaps even cleaner than from oil.  The problem, of course, is that biomass is neither a liquid nor a gas like these fossil fuels.  Burning a solid cleanly and efficiently is much more difficult.  Bulletin #2 dealt with cleanliness and the standards expected.  This one focuses on efficiency and how it can be measured for a biomass burner.
Instruments and software are available to deliver efficiency ratings and other data even to an ignorant user with enough money to buy them. But to use these tools intelligently, one must know how they function and should be able to calculate efficiency separately and from scratch.  This bulletin describes how to do that. 
Fundamentals
Efficiency is a concept that everyone understands, but different people often define it differently.  Let’s solve that problem first.  For simplicity, visualize a biomass combustor as a black box with fuel and air flowing in; flue gases and ash flowing out.[2] … As defined by logic, efficiency is the ratio of useful heat released to fuel energy provided.  Fuel Energy is the Higher Heating Value,[3] a quantity that has been carefully measured over the last couple centuries by scientists for all common fuels. 
For highest efficiency,
1.  Burn with the least amount of excess air possible.
2.  Operate with the lowest feasible flue gas temperature.
3.  Use dry fuel.
Alliance for Green Heat Data
The AGH study ran for a period of 30 days.  Investigators found results that showed little drift with time.  Five of the six stoves operated with more than 200% excess air; beyond maxima considered in Figure 7.  One could derive additional curves for these high air rates just as was done for the lower percentages of excess air, but I chose to extrapolate instead, creating the dashed lines in Figure 9.
Efficiencies for the six AGH pellet stoves as read from Figure 9b are listed in Table 6. 
Table 6.  Calculated efficiencies of pellet stoves studied in the September 2015 Alliance for Green Heat test series.
Stove                O2         % X’s Air           Flue Gas            Efficiency e                             
Brand                 Conc.    (Figure 8)           Temp. (oC)         (Figure 9b)
Enviro               18.7%       800%                        150                        51 %           
Ravelli              16.8%       400%                        195                        62 %           
Englander         16.0%       315%                        222                        63 %           
Quad                  17.4%       480%                        160                        64 %           
Harman             15.0%        245%                        205                        71 %
Piazzetta            13.5%       175%                        203                        76 %
One of the six operated at 51% efficiency, three in the low 60s, and the remaining two operated at 71 and 76%.  These numbers are consistent with the range mentioned in the AGH report. 
Piazzetta achieves superiority through low excess air rate. Enviro, at the other end of the spectrum, would have an even lower efficiency if its flue gas temperature were as high as the others.  All, except Enviro and Quad, appear capable of adding another 5 to 10 percentage points by increasing heat exchange area to reduce the flue gas temperature. 
Emissions
What about Pollution?  The AGH data demonstrate an interesting application of using “dilution as a solution to pollution.”[4]  The Harman emitted flue gases containing about 820 ppm CO while the Enviro emitted 534 ppm.  But the Harman operated with about 240% excess air; the Enviro with 800%.  And, the Harman was 22% more efficient. 
At the same pellet burning rate, the Enviro produces roughly 900/340 or 2.6 times as much flue gas as the Harmon, and its useful heat delivery rate is only 82 percent as great.  Thus, in terms of mass of CO per kJ of delivered heat, a better measure of actual pollution, the Enviro is (2.6/0.82)*(534/820) = 2.1 or about twice as bad as the Harmon.  Based on the data provided, I calculated mg of CO per MJ of useful heat delivered for the six pellet stoves.  Results are listed in Table 7. 
Table 7.  Calculated CO emissions of pellet stoves studied in the September 2015 Alliance for Green Heat test series.  
                                                                                                CO emissions    
 Stove                                                                     (mg/MJ of       (ppm)
Brand       % X’s Air           Efficiency e        (ppm)    heat   normalized**
Enviro               800%                51%                  534       3000     850  (2.7)
Ravelli              400%                62%                  428       1100    365  (1.2)
Englander         320%                62%                  542       1200    387  (1.2)
Quad                  480%                64%                  318         930     318  (1.0)**
Harman              240%                71%                  821       1300     487  (1.5)
Piazzetta            170%                76%                  648         780     370  (1.2)
           
                  *Normalized to Quad as the reference.
                  **Normalized to Quad as the reference using Wikipedia formula. 
In terms of mass per unit of useful heat, the Enviro emits about four times as much CO as the Piazzetta (3000 versus 780 mg/MJ or roughly 130 versus 35 milligrams per hour).
What about non-steady-state?  My analysis assumes the appliance operates at steady state with feed rates and temperatures invariant with time.  This is valid for automatic-feed pellet stoves but not for wood stoves that are fed batch-wise.  There, the burn mode migrates from de-volatilization and combustion of light organics, gradually progressing to char or carbon burn-out.  Fortunately, stage changes are slow relative to combustion kinetics.  At any given time, the analysis described herein can be used to analyze the appliance at that instant.  To more accurately reflect the performance of a batch-fired wood burner, one must record data over a complete firing cycle and then integrate results to obtain an average.  This is further complicated by the fact that heat of combustion changes with time.  That for carbon, for instance (near burn-out), is about 30,000 kJ/kg.  Since the overall HHV for biomass is 20,000 kJ/kg, that for the volatiles must be lower than this.

What about moisture condensation? Mark Knaebe advocates improving efficiency by increasing heat exchange surface to the extent that water in the flue gas is condensed, adding its latent heat to the useful Q.  This requires dropping flue gas temperature below the dew point.  With low amounts of excess air, the dew point might be as high as 60 deg-C, but with 400% excess air, where many pellet stoves operate, the dew point is nearer 30 deg-C.  
As cleaner appliances develop, the prospect of taking advantage of this extra heat becomes more intriguing because the condensate will be purer and non-fouling.  The added heat transfer surface and increased capital cost, however, may not be practical.  
Ray Albrecht suggests that temperatures in the range of 1000oC or greater are needed to achieve good burnout of flue gases.  He stresses the importance of preserving flame temperature by insulating the combustion chamber to make sure reaction is complete before gases enter the heat exchanger.
Staging the air feed can promote gasification and partial combustion at low excess air conditions where temperatures are higher.  Preheat can almost deliver a one-to-one increase of flame temperature with increased feed air temperature.  Staging and preheat are common in newer biomass burners. 
Catalysts are another important way to promote oxidation at lower temperatures than those needed otherwise.  



[1]Alliance for Green Heat press release [Oct. 27, 2015]  http://www.forgreenheat.org/decathlon/intro.html
[2]For simplicity, assume it is burning at “steady-state” where flow rates and temperatures are constant; not changing with time.  This is true of many pellet stoves and large-scale furnaces.  Small batch-fed systems do experience cycles and are more complex to analyze, but the steady-state analysis gives a useful result even for these systems.
[3]Unfortunately, fuel energy can be expressed in multiple ways, depending on how it was measured–giving different numbers for the same fuel.  As argued in BCI Bulletin #1, HHV or the Higher Heating Value is preferred and will be the only one considered here.
[4]A phrase attributed to the 20th century comic-strip character “Pogo.” 

Heated Up!

Study of pellet stoves shows environmental advantages – and corporate exaggerations

An independent assessment of popular pellet stoves conducted by the Alliance for Green Heat  found that pellet stoves, unlike most wood stoves, can achieve low levels of emissions in real world settings that are in line with laboratory results.   
The Alliance for Green Heat ran a battery of tests on popular pellet stoves designed to approximate how they would perform in the real world.  The group found that half of the stoves operated as clean at the end of the thirty-day test than they did at the beginning and the others were only slightly dirtier.
All six stoves, from the least to the most expensive, operated well, and produced enough heat for a small to medium- sized home in most of the United States.  One of the biggest differences was that the three more expensive stoves tested (above $ 4,000) needed very little weekly cleaning and maintenance.  The less expensive stoves ($ 1,200 to $ 3,300) needed daily or at least bi-weekly cleaning of their burn pots and glass.
The study also found a lack of accepted reporting standards, leading to exaggerated claims about efficiency, BTU output and pellet hopper size on manufacturer websites and promotional literature. 
The Alliance for Green Heat tested the stoves to give consumers better tools and make better purchasing decisions.  The study is part of a yearlong Pellet Stove Design Challenge that assesses the state of existing pellet stove technologies.  The Design Challenge will culminate in a competition for the cleanest and most efficient stoves, modeled after the Department of Energy’s Solar Decathlon.
Approximately one million American homes are heated with pellet stoves, more than twice the number that have solar panels.  In Italy alone, 2 million households heat with pellets. Pellet stoves often serve as primary heat sources, enabling homes to eliminate or drastically reduce fossil heating fuel.  Last year, about 40,000 pellet stoves were sold in the U.S. and they may outsell wood stoves in the near future.
The Alliance tested the England Stove Works 25-PDCVC, the Enviro M55 insert, the Harman Accentra 52i insert, the Piazzetta Sabrina, the Quadra-Fire Mt. Vernon AE, and the Ravelli RV80.  The group assessed each stove on its cleanliness, efficiency, maintenance, heat output and visibility of glass.  The overall winner was the Quadra-Fire Mt. Vernon AE, which received top marks in three of the five categories.  The Harman Accentra received top marks in two of the five categories.

The results of this study underscore that pellet stoves tend to burn substantially cleaner than wood stoves in real world settings, but it challenges the notion that pellet stoves generally have higher efficiencies than wood stoves.  The efficiencies of the six stoves were low to medium, which is partially the result of companies not having to test and report actual efficiency numbers. 
“Our testing confirmed that pellet stoves are an effective and affordable renewable energy technology,” said John Ackerly, President of the Alliance for Green Heat. “We hoped to see higher efficiencies, but efficiencies should improve in coming years,” Ackerly added.
Click here to read the full report.
The Alliance for Green Heat promotes modern wood and pellet heat as a low-carbon, sustainable and affordable residential energy solution. The Alliance works to advance cleaner and more efficient wood heating appliances and focuses on low and middle-income families.  Founded in 2009, the Alliance is a 510(c)(3) non-profit organization based in Maryland. 

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